Corrected offset for header #1676.

diff --git a/coders/jp2.c b/coders/jp2.c
index 63030715a6bcee1bca4c6396778974402734d0f8..ca887d0561e99b57965e71d9bdf26999d9f75524 100644 (file)
--- a/coders/jp2.c
+++ b/coders/jp2.c
@@ -147,9 +147,9 @@ static MagickBooleanType IsJP2(const unsigned char *magick,const size_t length)
     return(MagickFalse);
   if (memcmp(magick,"\x0d\x0a\x87\x0a",4) == 0)
     return(MagickTrue);
-  if (length < 12)
+  if (length < 16)
     return(MagickFalse);
-  if (memcmp(magick,"\x00\x00\x00\x0c\x6a\x50\x20\x20\x0d\x0a\x87\x0a",12) == 0)
+  if (memcmp(magick+4,"\x00\x00\x00\x0c\x6a\x50\x20\x20\x0d\x0a\x87\x0a",12) == 0)
     return(MagickTrue);
   return(MagickFalse);
 }

diff --git a/coders/jp2.h b/coders/jp2.h
index fc45935a278b6a51a35cf11def30d8fb943efdd2..84521b6dc1777822067f425947e02e77eee7e14c 100644 (file)
--- a/coders/jp2.h
+++ b/coders/jp2.h
@@ -17,7 +17,7 @@
 #include "coders/coders-private.h"
 
 #define MagickJP2Headers \
-  MagickCoderHeader("JP2", 0, "\x00\x00\x00\x0c\x6a\x50\x20\x20\x0d\x0a\x87\x0a") \
+  MagickCoderHeader("JP2", 4, "\x00\x00\x00\x0c\x6a\x50\x20\x20\x0d\x0a\x87\x0a") \
   MagickCoderHeader("JPC", 0, "\x0d\x0a\x87\x0a") \
   MagickCoderHeader("J2K", 0, "\xff\x4f\xff\x51")